diff --git a/Lib/subprocess.py b/Lib/subprocess.py
index 0dd55e0f74e..5684d523952 100644
--- a/Lib/subprocess.py
+++ b/Lib/subprocess.py
@@ -1149,7 +1149,11 @@ class Popen(object):
                 os.close(errpipe_read)
 
             if data:
-                _eintr_retry_call(os.waitpid, self.pid, 0)
+                try:
+                    _eintr_retry_call(os.waitpid, self.pid, 0)
+                except OSError as e:
+                    if e.errno != errno.ECHILD:
+                        raise
                 child_exception = pickle.loads(data)
                 for fd in (p2cwrite, c2pread, errread):
                     if fd is not None:
@@ -1195,7 +1199,15 @@ class Popen(object):
             """Wait for child process to terminate.  Returns returncode
             attribute."""
             if self.returncode is None:
-                pid, sts = _eintr_retry_call(os.waitpid, self.pid, 0)
+                try:
+                    pid, sts = _eintr_retry_call(os.waitpid, self.pid, 0)
+                except OSError as e:
+                    if e.errno != errno.ECHILD:
+                        raise
+                    # This happens if SIGCLD is set to be ignored or waiting
+                    # for child processes has otherwise been disabled for our
+                    # process.  This child is dead, we can't get the status.
+                    sts = 0
                 self._handle_exitstatus(sts)
             return self.returncode
 
diff --git a/Lib/test/subprocessdata/sigchild_ignore.py b/Lib/test/subprocessdata/sigchild_ignore.py
new file mode 100644
index 00000000000..1d03303e447
--- /dev/null
+++ b/Lib/test/subprocessdata/sigchild_ignore.py
@@ -0,0 +1,6 @@
+import signal, subprocess, sys
+# On Linux this causes os.waitpid to fail with OSError as the OS has already
+# reaped our child process.  The wait() passing the OSError on to the caller
+# and causing us to exit with an error is what we are testing against.
+signal.signal(signal.SIGCLD, signal.SIG_IGN)
+subprocess.Popen([sys.executable, '-c', 'print("albatross")']).wait()
diff --git a/Lib/test/test_subprocess.py b/Lib/test/test_subprocess.py
index 2379b3e5fe4..adf00a50a07 100644
--- a/Lib/test/test_subprocess.py
+++ b/Lib/test/test_subprocess.py
@@ -793,6 +793,17 @@ class ProcessTestCase(BaseTestCase):
                 stdout = stdout.rstrip(b'\n\r')
                 self.assertEqual(stdout, value_repr)
 
+        def test_wait_when_sigchild_ignored(self):
+            # NOTE: sigchild_ignore.py may not be an effective test on all OSes.
+            sigchild_ignore = support.findfile("sigchild_ignore.py",
+                                               subdir="subprocessdata")
+            p = subprocess.Popen([sys.executable, sigchild_ignore],
+                                 stdout=subprocess.PIPE, stderr=subprocess.PIPE)
+            stdout, stderr = p.communicate()
+            self.assertEqual(0, p.returncode, "sigchild_ignore.py exited"
+                             " non-zero with this error:\n%s" % stderr)
+
+
     #
     # Windows tests
     #
diff --git a/Misc/NEWS b/Misc/NEWS
index 0f9a7853984..058b02a6971 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -35,6 +35,10 @@ Library
 
 - Issue #10464: netrc now correctly handles lines with embedded '#' characters.
 
+- Issue #1731717: Fixed the problem where subprocess.wait() could cause an
+  OSError exception when The OS had been told to ignore SIGCLD in our process
+  or otherwise not wait for exiting child processes.
+
 Extensions
 ----------